Centrifuge



Aug. 23, 1966 R. KERN 3,268,159

CENTRIFUGE Filed Oct. 11, 1963 Fig] 73 7 72 2 3 70 8 3a 77 INVENTOR.

ROBERT KERN Y ILM . P I, i O r 3,268,159 Patented August 23, 1966 ,1{Jails/i011 less than the outside diameter of the rotating CENTRIFUGERobert Kern, Heidenheim, Germany, assignor to J. M. Voith G.m.b.H.,Heidenheim (Brenz), Germany Filed Oct. 11, 1963, Ser. No. 315,477 Claimspriority, application Austria, Oct. 16, 1962, 8,153/62 4 Claims. (Cl.233-7) This invention relates to a centrifuge for the separation ofsolids from the liquid component of a mud. A centrifuge of this kind hasa rotationally symmetrical body on the outer surface of which is mounteda helically elongated or screw flange for moving the solids in axialdirection during rotation of the body. Around the outside of the bodyand mounted for rotation coaxially therewith is a rotatable drum, spacedfrom the outer surface of the body to permit rotation of the body andits screw flange inside the rotating drum so as to move the solidsaxially in one direction. The mud is introduced at one end of theapparatus into the space between the body and the drum and is then putinto rapid rotation in that cylindrical space. The specifically heaviersolids will be separated from the liquid by centrifugal force and willbe deposited on the inner surface of the drum. Slow rotation of thespiral flange relative to the drum will then gradually move thedeposited layer of solids toward the other end of the drum from whichthey will be discharged through openings in the drum. At the same timethe centrifuged liquid enters the interior of the rotating body throughradial openings between the convolutions of the screw flange and flowsaxially in a direction opposite to the direction of movement of the muduntil it reaches the front end of the rotating body from where itescapes to the outside through openings in the same end wall of the drumthrough which the mud enters.

The liquid which, in the prior devices of this kind, enters the rotatingbody through its radial openings is under centrifugal force whichopposes such entrance. The liquid will therefore enter the body withreduced velocity, which will result in separation of residual solidsfrom the liquid, and these will be deposited in the radial openings ofthe body so as to reduce the throughput through the machine.

Furthermore, since the flow of liquid along the interior of the hollowbody is slower than its speed of entrance through the radial openings,there will also be further sedimentation inside the hollow body whichmay eventually result in complete occlusion of the radial open ings soas to render the centrifuge inoperative.

Furthermore, in centrifuges of this type, the separated liquid,during-its passage across the transitional space between the end wall ofthe rotating body and the end wall of the drum, will become contaminatedwith solids from the entering mud which must also pass across thistransitional space.

These difliculties of the prior centrifuges of this kind are avoided bythe present invention where the liquid which has entered the rotatingbody through its radial openings is conducted through a plurality ofnarrow conduits to the other end of the body so that its velocity offlow in the axial direction will not be diminished to such an extent asto result in further deposition of solids.

The conduits for removing the separated liquid reach at least part Wayinto the rotating body. These pipe-like conduits generally extend partlythrough the rotating body and partly through the rotating drum, theentrance of the conduits being at the same radial distance from the axisof rotation of the body and drum as the centrifuged liquid, whereas theexit of the conduits is equidistant from or nearer to the axis ofrotation. It is generally best to have the radial distances of theconduits from the axis of In some cases, especially where the space thatcontains the screw flange is of large radial extension, it may beadvantageous to pass the conduits that lead to this space directlythrough the end wall of the drum, so as to avoid the necessity ofpassing these conduits through any part of the rotating body.

In another form of this invention, the pipe-like conduits are positionedsubstantially parallel to the axis of rotation, to simplify themanufacture thereof.

In order to obtain separated liquid iinactions of different degrees ofpurity, the conduits for conducting away such liquids are arranged atdifferent distances from the axis of rotation with provision forcollecting and discharging these fractions separately.

In the drawing which shows, in schematic arrangements, three embodimentsof the centrifuge of this invention FIGURE 1 is a longitudinal sectionof a partly conical centrifuge;

FIGURE 2 is a longitudinal section of a portion of a conical centrifugewith its discharge conduits partly in the rotating body and partly inthe rotating drum;

FIGURE 3 is a longitudinal section of a portion of a partly conicalcentrifuge with two liquid discharge passageways.

In these three figures, equivalent parts are designated by the samereference characters.

In FIGURE 1 the centrifuge has rotatably mounted on its housing 1 apartly conical drum 2 formed as an assembly of three major parts, and apartly conical body 3a .with a helically extended flange 3 rotatablymounted in the drum. The body 3a which with its flange 3 and the drum 2are mechanically driven from the narrow end of the centrifuge by a motoror other mechanism for rotation at high but somewhat different speeds inthe same direction. The mud is delivered to the annular space 7 betweenthe drum and the body by means of a supply conduit consistingessentially of a stationary pipe 4 extending into and forming a liquidtight joint with the hollow open end of the drum 2 that is opposite itsnarrower driven end, the conduit terminating in radial canals 6 withadjacent pump blades 5. The mud which is delivered to the annular space7 forms a ring 8 under the influence of the centrifugal force of therotating drum 2, in which the heavier solids 9 (indicated by the brokenarrows) and the lighter liquid 10 (indicated by the solid arrows) areseparated from each other. The solids 9 are discharged through openings11 in the conical portion of the drum 2 by means of the spiral flange 3,while the liquid 10 passes through a plurality of pipes 12 in the body3a equally spaced and parallel to its axis of rotation, and then throughboreholes 13 in the end wall of the outer drum 2 for discharge into thehousing 1.

In the centrifuge of FIGURE 2, the mud is delivered to the annular space7 and the solids then discharged through openings near the other end ofthe drum in the same manner as in FIGURE 1. The discharge of the liquidhowever occurs in a different manner than in FIG- URE l. The liquid 10is here delivered from the annular space 7 through pipes 12a in the endwall of the drum 2 to the discharge apparatus 13 which is common to allthe pipes. This discharge apparatus consists of a narrow circularchamber 13a provided with entrainment ribs 14 and a number of equallyspaced radial collecting pipes 15 which continually remove thin layersof the liquid 10 which is delivered by the pipes 12a to the chamber 13a.The pipes 15 empty into a stationary discharge conduit 16 passingthrough the hollow hub of the drum 2 for delivering the liquid to theoutside.

In certain cases where the radial dimensions are ade- 9 a quate, anadditional series of pipes 12b closer to the axis of rotation than thepipes 12a, and associated therewith an additional discharge apparatus13b positioned in the body 3a, can be provided as shown in FIGURE 2,whereby liquid samples of different degrees of purity can be removedsimultaneously. By locating the discharge apparatus 13b in the rotatingbody 3a, the necessity for bore holes 12a through the end wall of thedrum 2 is avoided.

With the construction shown in FIGURE 3, two separate liquid dischargesystems 13 together with their respective series of pipes 1212 arearranged in the rotating body 3a for removing liquid portions ofdifferent degrees of purity. The construction shown in FIGURE 3 can alsoinclude in it the liquid removal system shown in FIG- URE 2 where theliquid is passed directly from the annular space 7 through pipes 12a andinto a circular chamber 13a in the end wall of the drum.

In each of the three constructions shown in the drawings, the pipes orpassageways 12, 12a, 12b in the rotary body 3a are parallel to the axisof rotation and symmetrically distributed around said axis. The greatestpossible degree of symmetry is maintained in the design of all the partsto ensure smoothness of operation. In each case these pipes orpassageways are sufficiently narrow and restricted in cross-section togive the liquid that passes through them a velocity high enough toprevent therein any deposition of solids from the separated liquid.

Although various forms of this invention have been shown withconsiderable precision, it is to be understood that the invention is notrestricted to the specific details of construction that have been shownand described, unless such details are recited in the claims.

What is claimed is:

1. A centrifuge for the separation of dispersed solids from a mud, saidcentrifuge comprising a continuous rotatable body carrying on itsradially outer surface a helically elongated screw flange, a rotatabledrum surrounding the body and mounted for rotation relative to the body,one end of the drum being provided with an end-wall carrying a centralhollow shaft for rotatably supporting the drum the end-Wall havingconduit means for conducting the mud into the annular space between thebody and the drum, the outer periphery of said flange substantiallyfitting the adjacent wall of said drum, the opposite end of the drumbeing of reduced diameter and having openings in it for the discharge ofsolids which have been moved by the screw flange to that end of thedrum, and passageway means in said body extending lengthwise of the axisof rotation thereof opening at one end into said annular space andextending through an end portion of said body for conducting theseparated liquid away from said annular space, said passageway meansbeing of restricted cross-section to prevent the deposition therein ofsolids from the separated liquid.

2. The centrifuge of claim 1, in which the restricted passageway meansextend parallel to the axis of rotation of the body.

3. The centrifuge of claim 1, in which the restricted passageway meansare arranged in separate groups of passageways at different distancesfrom the axis of rotation and discharging their liquids separately, theindividual passageways of each group being at the same distance from theaxis of rotation.

4. The centrifuge of claim 1, in which said passageway means includes achamber in said rotatable body and a stationary collecting pipepositioned in the chamber for the removal of liquid from the chamber.

References Cited by the Examiner UNITED STATES PATENTS 1,780,655 11/1930Nyrop 233-7 1,806,241 5/1931 Dupuis 2337 2,614,748 10/1952 Ritsch 23372,711,854 6/1955 Kjellgren 2337 M. CARY NELSON, Primary Examiner.

HENRY T. KLINKSIEK, Examiner.

1. A CENTRIFUGE FOR THE SEPARATION OF DISPERSED SOLIDS FROM A MUD, SAIDCENTRIFUGE COMPRISING A CONTINUOUS ROTATABLE BODY CARRYING ON ITSRADIALLY OUTER SURFACE A HELICALLY ELONGATED SCREW FLANGE, A ROTATABLEDRUM SURROUNDING THE BODY AND MOUNTED FOR ROTATION RELATIVE TO THE BODY,ONE END OF THE DRUM BEING PROVIDED WITH AN END-WALL CARRYING A CENTRALHOLLOW SHAFT FOR ROTATABLY SUPPORTING THE DRUM THE END-WALL HAVINGCONDUIT MEANS FOR CONDUCTING THE MUD INTO THE ANNULAR SPACE BETWEEN THEBODY AND THE DRUM, THE OUTER PERIPHERY OF SAID FLANGE SUBSTANTIALLYFITTING THE ADJACENT WALL OF SAID DRUM, THE OPPOSITE END OF THE DRUMBEING OF REDUCED DIAMETER AND HAVING OPENINGS IN IT FOR THE DISCHARGE OFSOLIDS WHICH HAVE BEEN MOVED BY THE SCREW FLANGE TO THAT END OF THEDRUM, AND PASSAGEWAY MEANS IN SAID BODY EXTENDING LENGHTWISE OF THE AXISOF ROTATION THEREOF OPENING AT ONE END INTO SAID ANNULAR SPACE ANDEXTENDING THROUGH AN END PORTION OF SAID BODY FOR CONDUCTING THESEPARATED LIQUID AWAY FROM SAID ANNULAR SPACE, SAID PASSAGEWAY MEANSBEING OF RESTRICTED CROSS-SECTION TO PREVENT THE DEPOSITION THEREIN OFSOLIDS FROM THE SEPARATED LIQUID.